Broca's area in the frontal lobe is responsible for grammar (syntax and morphology) and Wernicke's in the temporal lobe is responsible for semantics.

Language is a signal system and a socially shared code. Since it is a shared code, we can represent one thing with another. For example, you can convey the idea of “desert” to a listener by using the symbol (word) without having to describe a desert, show a picture of a desert, or take your listener there. The speakers of a language have agreed amongst themselves which symbols should be used.
Language is a generative system. The product generated is a message.
Language is a dynamic, rule-governed system described by at least 5 parameters: phonology, morphology, syntax, semantics, and pragmatics.
All languages are essentially equal in expressive capacity; there is prejudice against some dialects for social reasons, not because of inherent deficiencies.

Pidgin is a simplified, limited purpose language, a language of commerce

• Creole is a complete language developed from pidgin. Children are reared by adults who speak pidgin and their subsequent language is called creole. Some consider it to be a dialect of English. Others view it as a distinct language, learned naturally.

Theories ofLanguage Acquisition

Behaviorism

Associated with Watson and Skinner, it holds that language is learned through imitation and need. It uses behavior modification to explain how language develops through trial and error and selective reinforcement. It denies that there are specific language centers in the brain.

Nativism

Associated with Chomsky, nativism holds that humans are biologically wired to acquire language. He holds that there is a language acquisition devise (LAD) (language centers) in the brain that can decode random speech and turn it into a grammar without any type of parent child interaction. According to Chomsky language gets to the brain through the auditory system and that the LAD will turn this randon speech into grammer (syntax and morphology).

This is associated with Brown, Bloom, and Bruner. It lies between the two extremes. It borrows from both behaviorism and nativism. There is some biological predisposition to learn language but more than mere exposure is required. Language learning requires a specific type of interaction with an adult model. It is a little closer to nativism than to behaviorism. The environment and constitutional factors both contribute to development.

Jerome Bruner says "tongue in cheek:" if there is a LAD, it is up in the air between the mother and child. The child has a predisposition to acquire language through motherese; parents are predisposed to use motherese.

Sociolinguistic/pragmatic

This perspective came from Bloom and Lahey and also from Fey.
Bloom and Lahey: Content, semantics-the what of language.
Referential knowledge-understanding of objects, events and relations, underlying word meaning.
Relational knowledge-roles of objects in relation to action, in relation of events to one another, etc.: rules specifying the relationship between form and content. Pragmatics is the social/ practical aspect of language including the how, why, when, and where of language.

The interactionist perspective takes from the other four theories of language acquisition.
According to the interactionist perspective, language development depends on interaction with the parent and others in the child’s life in a natural way. Motherese is used through the child’s day. Reinforcement is based on naturally occurring contingencies. For example, if the child says “more,” the mother gives him/her more milk. The child learns the power of language. (A behaviorist might give the child a raisin or sticker for verbalizing and require the child to: “say the whole thing. I would like more milk please.” before getting the milk.) Teaching children these little unnatural phrases will disrupt the flow of natural language learning. In natural communication between child and caregiver no one says "say the whole thing," but many therapists do.

The interactionist perspective began with Roger Brown at Harvard University and Margaret Bullowa of MIT. Graduate students followed a number of children over several years (longitudinal study): Adam, Eve and Sarah. This research helped explain how language developed. The term motherese is used to describe the way a mother interacts with her child to optimize language development. For example parents typically only correct semantically untrue utterances not grammatically incorrect utterances. So they will correct "horsie" to describe a cow, but not “Daddy runned” or "Mommy hided it."

According to Lenneberg, a maturationist, the development of language is contingent on brain maturation. He says that there is a critical period for language acquisition from 2yrs to 13 yrs. If a child doesn't learn a language during that time frame, he/she will never be a truly fluent speaker of the language. I believe that all of the time from birth to age 8 is quite critical. (There are lots of important milestones in language acquisition that occur before the end of the first year, object permanence, means-end knowledge, etc.) Many children don't use the passive voice until age 8.
The very interesting case of Victor, the wild boy of Avignon, supports Lenneberg’s hypothesis. Victor had no exposure to language between 2 and 13 yrs. Although he amassed a good sized vocabulary, and learned word order rules, he never mastered morphological inflections, auxiliary verbs, or the passive voice. Also, his speech remained phonologically abnormal.

Pre-language development

The perlocutionary period

The perlocutionary period is from birth to around 7 months. Without conscious thought the child communicates his/her needs through cries and facial expression. None of the cries or gestures that s/he makes are intentional. During the perlocutionary period the child does not intend to communicate, but parents interpret vocalizations, gestures, etc. as communication. This adult morphizing helps bring the child into intentional communication.

The illocutionary period:

It begins around 7 months and ends around around 12 months. The child communicates through gestures and vocalizations that are meaningful and precede the first true words.

In terms of development, the ability to intentionally communicate develops before speech. At age one, speech takes over the role previously filled by gestures, etc. Finally the child is using words to convey meaning. In fact meaning drives word order through the two, three and four word stages.

The locutionary period:

The locutionary period begins around 12 months or when the child begins to use words to communicate. Some normal children may not talk until 18 to 24 months, but they have receptive language.

Lecture 2: Phonology/phonemics

Phonology

Phonology/phonemics is the study of the sound system of a language. The rules for structure, distribution and sequencing of speech sounds and the creation of word meaning through phoneme sequencing.

• Phonemes are the speech sounds of a language. They aren't meaningful by themselves, but they are the smallest linguistic unit of sound that can signal a difference in meaning. Some languages have as few as 12 phonemes; English has 44 phonemes.
Phonemes can be distinguished from one another by manner: or the way in which the air stream is obstructed, by place: the location of the obstruction, and by voicing: whether or not the vocal cords are vibrating.

One can’t say that a child has acquired phonemes until s/he uses them in words. Before the first word, s/he may be making sounds that are identical to phonemes phonetically, but they aren’t being used to produce meaning, so we can’t say that they are true phonemes.

Phonetics

Phonetics describe the articulatory movements required to make sounds. For example: /b/ is a voiced, bilabial, stop, plosive.Phonetic vs. phonemic difference: A phonetic difference doesn’t involve a difference in meaning. It is a nonfunctional difference. A strictly phonetic difference would be the contrast between two allophones of a phoneme. For example: light /l/ vs. dark /l/ in /li/ (fronted vowel) and /lu/ (back vowel respectively. There is a sound difference, but no change in meaning. Another example of a phonetic difference is /pit`/ with an aspirated (puff of air) /t'/ and /pit-/ with an unreleased /t-/ where the tongue tip remains on the alveolar ridge. An unaspirated /t"/ occurs after /s/ as in words like /stop/.

In Chinese and Japanese and some other Asian languages the phonemes /r/ and /l/ are allophones of the same phoneme, not different phonemes as in English, so many Asian speakers don't hear the difference between these sounds.
The allophones of a phoneme can be in complementary distribution: where one appears the others do not, e.g. aspirated and unaspirated (/p/,) or in free variation, where they can be used interchangeably e.g. "sit" (aspirated) and "sit-" (unreleased). Unaspirated plosives occur after a fricative. e.g. the /s/ phoneme in the word spin is unaspirated, meaning there is no puff of air.

A phonemic difference signals a difference in meaning between two words that differ by one phoneme (a minimal pair). A phonemic difference also results in a phonetic difference. The words /big/ and /pig/ are minimal pairs differing by just one phoneme and actually by one feature, voicing. With /b/ and /p/ place and manner are the same, only voicing is different.

Minimal pair contrasting was used originally by linguist anthropologists to analyze new languages by discovering which sounds were phonemic, therefore knowing the phonemes of that language. In spring of 2008 a previously unknown tribe with a language never heard before was discovered in the Amazon basin.

Minimal pair contrasting is also used by some language clinicians to decide if a child has acquired a particular phoneme. This example of a child's use of /th/ illustrates the concept: if a child substitutes /t/ for /th/ in the initial position of the word "think" it becomes /tink/ but uses /f/ in the final position of the word teeth it becomes /teef/ these two sounds /t/ and /f/ are allophones of the /th /phoneme for that child.

Phonotactics (syllable structure)

Phonotactics is the study of syllable structure; it is part of phonology. The syllable is the language unit greater than a phoneme, and typically smaller than a word, although some words have only one syllable.
These syllable forms develop in the context of words. A child doesn't’t start to use syllables until s/he starts to use true words.
The first words will often be vowels (V) consonant and vowel (VC) or vowel and consonant (VC).

1. Every syllable must have a vowel nucleus. So the simplest syllable form possible is (V).

2. CV is the next level up in terms of complexity. There are some phonological restrictions that occur here:
/NG/+V does not occur in English

3. VC form V+/h/ does not occur in English
V+ /w/ “ “ “
V+ /j/ “ “ “

4. CVC is a big step up in complexity. The closing off the syllable can be quite difficult. The rules for #2 and #3 apply here. Many children with delayed language fail to close the syllable, e.g. (ca) for cat.

5. CCV is another big jump in complexity. It is a consonant cluster. Various combinations are not permitted here /tl/, /zr/, etc. In addition, the restrictions for #2, apply here.

6. CCVC contains a consonant cluster and a closed syllable. it is also subject to the restrictions for 2, 3, and 5. An example of CCVC would be the word spoon.

7. CCVCC is also subject to restrictions for 2, 3, and 5. An example would be (spilled).

8. CCCV doesn’t allow combinations of 4 or more consonants to cluster in English. There aren’t very many 3 consonant combinations either. Some examples: spring, screamed and splashed.

Phoneme Development. The best known theorist in this area, Roman Jakobson, said that the phonological system begins with a small set of distinctive features, which grows to a larger, finite set of features in a given language.

Distinctive features are the acoustic or articulatory characteristics of a phoneme that distinguishes it from others. Manner, place and voicing is the simplest distinctive features system.
According to Roman Jakobson, phoneme development follows a system of maximal differentiation. The first words are comprised of sounds that are maximally different e.g.: /ma ma/ is frequently the first word. The initial consonant /m/ is a bilabial and the second /a/ is a back vowel. Jakobson feels that additional phonemes develop in the same way with differences becoming finer.

Development of phonemes and phonetic substitutions are related. The fewer features a child has, the fewer phonemes are possible, the more substitutions s/he will make (fewer different types of substitutions though, as child will have a small number of phonemes). The /s/ and /z/ phonemes do not emerge until the child has the /t/ and /d/ phonemes for some time. Phonemes like /s/ and /z/ that develop late are replaced more often by ones that develop earlier. Ninety percent of substitutions are replacements of sounds that a child doesn’t have with one s/he does have. For example a child may replace /s/ with /t/ as in "tee" for "see." In this case /t/ is an allophone of /s/.

• Simplification processes are used by young children when they are unable to pronounce words that are beyond their ability. Children simplify in several different ways.

1. deletion is also called reduction /ba/ for /ball/ /piz/ for /please/
2. assimilation can be regressive /gogi/ for /dogi/ or progressive /dodi/ for dogi/
When the phonetic system can’t handle two phonemes in a word, the child creates one for both.
3. Substitution or substituting a simpler phoneme for a more complex one, teef for teeth, The allophone /f/ for the phoneme /th/ is common. I call it an allophone because it is a variant of the /th/ phoneme. Other allophones of /th/ for an individual child could be /t/or /s/.

Children with phonological disorders have fewer phonemes and phonemic contrasts than typically developing children. Phoneme collapse is a term used to describe the child’s use of one phoneme for several, e.g., /t/ for t, s,and th,

Many people are confused about the term grammar. Grammar describes syntax (rules of word order and inflected morphemes ): morphology. In this context morphology refers to inflected morphemes (allomorphs/inflected morphemes). Note that morphology in this context refers only to allomorphs.

Morphology described broadly

Morphology is the study of words; the study of how words are formed. It has to do with the internal organization of words.
A morpheme is the smallest unit of meaning in any language. Free morphemes are words that can stand alone. Chairperson consists of two free morphemes. In the word“explain,” plain while being a free morpheme by itself adds nothing to the meaning of “explain.”

• Bound morphemes cannot stand alone: they are suffixes and prefixes. For example: chair + s = chairs. Chair is a free morpheme, and “s” is a bound morpheme, in this context called the plural inflection or allomorph. Another type of bound morpheme is a derived morpheme. An example is the "ly" in badly. Another example is the morpheme "dis" as in display. Inflected morphemes can only be suffixes, while derived morphemes can be affixes, either prefixes or suffixes.

Grammatical morphemes

This category includes both inflected morphemes and some function words like a, an, the, in, and on. So some are free morphemes, and some are bound, inflected morphemes.

Grammar is defined as syntax + inflected morphemes. In other words grammar is word order + inflected endings. Grammar describes the relationship between words and smaller units such as the plural “s,” between words and meaning, between words and communication intent.

Inflected morphemes

An inflected morpheme is also called an allomorph. Each allomorph is both a phoneme and a morpheme. Allomorphs are formed by morpho-phonemic rules. The term “morpho” because a meaningful unit is involved, and “phonemic” because a sound change has occurred. Inflected morphemes unlike derived morphemes (derivations) are learned according to rules. Rules in this context means regularities. This is proved by the child’s regularization of irregular nouns and verbs. For example children will first learn “run/ran;” then when they learn the past tense inflection they will change it to “runned.” Another example is plurality. Child learns mouse and then mice but when they acquire the plural allomorph/inflection they will say “mouses.” Both “runned” and “mouses” are called creative errors, and should be reinforced and not corrected.

Inflected morphemes are always suffixes. They are a sub-class of grammatical morphemes. So all inflections are grammatical morphemes but not all grammatical morphemes are inflections (test question). The article ”a” is a grammatical morpheme, but not an inflection. When an inflected morpheme is added to a word it doesn’t change the grammatical class of the word (from a noun to an adjective, for example), while derived morphemes when added to a word almost always change the grammatical class of the new word (e.g. bad+ly= badly. "Bad" is an adjective and “badly” is an adverb. Many so called educated people say "I feel badly" when they express their sorrow about some issue. A very popular columnist for the San Francisco Chronicle, Charles McCabe, coined the term "half educated" to describe people who hyper-correct. They should say "I feel bad," but they think it sounds more educated to say "badly." I've noticed both George Bush and Barack Obama say it.

There are only nine inflected morphemes in English, while there are numerous derived morphemes. Inflected morphemes are morphemes like plurality, possession, plural, etc. Inflected morphemes are typically learned by children in an invariant order. Some children have trouble learning them, so their acquisition is considered an important stage in language development. When we compute a mean length utterance we count words and inflected morphemes and divide by the number of utterences.

The 9 Morphological Inflections/Allomorphs:

Some of the inflections included in Brown’s list of 14 morphemes can be considered as a group to constitute the next milestone in the child’s language development, mainly because they are really difficult for children. This is where a child who’s having problems with language might flounder.

1. Ing is acquired around 28 months or earlier. It is easily acquired by most children.

2. Plural /S/ /Z/ /IZ/. This should develop shortly before age 3 if the child does not have a problem. It is difficult to learn because the child is exposed to so many different models, as well as the short duration of the allomorph.

3. Possession /S/ /Z/ /IZ/. Should be learned by age 3 or a little after (before 3 ½).

This is not about the concept of possession, just a new way to express it.
This was previously expressed as modifier + head recurrence form: “nuther cookie”, “more milk.”
The possession concept is probably acquired at one word stage or before. In case grammar it is expressed as modifier + head: “my teddy,” “mommy sock.”
“mommy want chocolate candy” Four word stage, but prior to the possessive inflection.

4. Regular past tense /t/ /d/ /Id/ acquired by 3.5 or a little after.

5. Third person singular regular present tense verb is acquired after 3.5. Note that this morpheme has the same phonemes as with plural and possession.

So from 2.5 to 3.5 or four the child moves from ing to 3rd person singular/regular verb.
According to Brown, a child is said to have not developed a morpheme unless he/she’s using it in 90% of obligatory contexts. But if child is using these 60% or so of the time at the above ages, they are probably acquiring language normally.

If a child attaches the plural inflection to the word boy to make boys that is obligatory and it's marked. The word man doesn't take an allomorph, because its irregular. The plural is men. So that is not marked.

6. When the auxiliary "to be" in the 3rd person singular (e.g. she is listening) is contracted to (she's listening) the /z/ sound after she is an allomorph.

7. The copula 3rd person singular "to be" when contracted the z sound is an allomorph.

8. The comparative "er" in the word nicer is an allomorph.

9. The superlative "est" in nicest is an allomorph.

Dialects of English

Derived morphemes

Derived morphemes may either be suffixes or prefixes. These do (most of the time) change the grammatical class of the word to which they are attached. Examples are: kind (adjective)+ly=kindly(adverb), kind+ness=kindness(noun). They are typically from Greek and Latin. Although there is controversy I believe that they are learned as vocabulary items in combination with the free morphemes to which they are attached rather than as a rule or regularity that's seen with inflected morphemes..

Syntax

The most basic sentence is a SADA. It is called a kernel sentence: Simple (one idea) Active (not passive) Declarative (statement not ask a question) Affirmative (not negative). To be a kernel sentence it has to be simple, active, declarative and affirmative.

The rules for word ordering are called syntax. They specify which word combinations are acceptable or grammatical.
Example: “She is nice” vs. “Is she nice.” The words are the same but the meaning is changed by the word order. The basic requirements for a sentence are a noun phrase and a verb phrase combination.

Later, omitting the auxiliary or not developing interrogative reversals or verb negation are all are problems of syntax.

An example of a problem with early syntax: word order reversal at two-word stage, saying “run daddy” instead of “daddy run.” (this is a problem with a semantic- syntactic rule. The word order in this early stage is based on meaning (case grammar). Case grammar is used to describe language development at the 2, 3, and 4 word stages. A case is the semantic role for a noun. If a child says "Daddy house" meaning daddy is in the house (locative case) or if the child meant that Daddy owned the house that would be a different semantic case for daddy (modification). Fillmore used case grammar to account for language acquisition at the two, three and four word stages.

Lecture 4: Semantics

From the two word stage through the four word stage meaning dictates word ordering.

Meaning and competence versus performance

The study of word and sentence meaning is calledsemantics. It is a subset of cognition. Word meaning evolves through episodic memory or the memory for specific events/experiences. Many such events give rise to semantic memory or word/symbol definitions. It is primarily verbal. The terms content, form and use refer respectively to meaning, (semantics) grammar, (syntax and morphology) and use (pragmatics).Cognitive knowledge is knowledge of the world. Semantic knowledge the pairing of concepts with linguistic units; concept-language links.
Each word is characterized by its semantic features (markers) and selection (selective) restrictions.Semantic features are the aspects of meaning that characterize words. For example: “mother” includes the features female and parent; father includes male and parent; bachelor means male and unmarried. Selection restrictions are based on semantic features (aspects) and prohibit contradictory word combinations such as “bachelor’s wife.”

Young children have different semantic markers for words than adults; they sometimes violate rules based on selection restrictions (e.g., she is a boy).

The meaning of a sentence is more than the sum of the meanings of the words combined to form the sentence. “The boy loved the girl” and “The girl loved the boy” contain the same words but have different meanings.
So, meaning can be affected by word order and also by paralinguistic and nonlinguistic cues, not just a product of individual word meanings.

Linguistic Competence

Competence is knowledge of the rules of a language. This will generally be an implicit knowledge. We can’t measure competence directly. Rules for grammar, semantics, pragmatics, etc.

Linguistic Performance

Performance is use. Performance is the use of the rules of language. This includes both production (expression) and comprehension (reception.) So when people talk or write or sign they are using the rules of language (production). When they listen to a book on tape or read they are using rules of language comprehension. Performance can be measured. Only through performance we can determine competence.

Lecture 5: Pragmatics

Pragmatics is the practical and social use of language. Knowing how to use social and cultural rules to communicate is called pragmatics. It is the aspect of language use (function) within a communication context. It is knowing when and how to say what to whom.
It has to do with the effectiveness of language to achieve goals, and knowing how to use paralinguistic codes and nonlinguistic cues. Some other pragmatic behaviors are knowing how to greet, take leave, and initiate and maintain a conversation.

Paralinguistic codes

Some examples of paralinguistic codes are intonation, stress or emphasis, speed, or rate or delivery, and pause or hesitation superimposed upon speech to signal attitude or emotion.
They are also called suprasegmental devices because they can change the form and meaning of a sentence by acting across elements or segments of a sentence.
Example: “They are sailing boats” (those boats are for sailing)
“They are sailing boats” (those people are sailing boats)
“I hate you” could be an expression of antipathy or of affection depending upon the tone of voice.

Intonation or the linguistic use of pitch is the most complex of the paralinguistic codes and is used to signal the mood of an utterance.
Stress is employed for emphasis.
Pitch along with loudness and duration is used to add to content.

Nonlinguistic cues

Some examples of nonlinguistic cues are: gestures, body postures, facial expressions, eye contact, head and body movement and proxemics or the distance between conversational partners.

Metalinguistic cues:

They signal the status of transmission or the success of communication. The ability to talk about language, analyze it, see it as an entity separate from its context is a metalingusitic act. For example, knowing that an utterance doesn't’t sound right.

Bloom and Lahey were among the first to come up with the terms form, content and use:Form: syntax, morphology, phonology Content: semantics (meaning) Use: pragmatics (social/functional)

• Margaret Lahey has discussed categories of pragmatic knowledge and skills:
knowing how to use language for various goals or functions (learning to persuade somebody to act in a particular manner),
using information from context to determine what to say in order to achieve personal and social goals. One has to pick the right form for each context.

One has to make judgments about what one’s listener already knows,Pre-supposition are judgments about the capacity and needs of listeners in different social contexts.Conversational ability: rules of cooperative exchange; knowing how to initiate, maintain and terminate a conversation. Maintenance includes skills in taking turns, knowledge of how to assert, and how to respond or react to the other person. These are called conversational postulates.

Speech Acts

Remember that speech act theory is a pragmatic theory

Direct: the intention is reflected in their syntactic form. Example, “answer the phone.”Indirect : the intention is not reflected in the syntactic form. Example, “could you answer the phone?” you arena’t really asking if the person is capable of doing this. Ask me how I quickly learned the difference after I immigrated to the U.S.
Speech acts can also be literal or non literal (sarcasm, etc.).

According to Austin, speech acts can be analyzed into three parts:locutions or propositions

illocutions or intentions

perlocutions or the listeners interpretation

Grice's maxims describe the cooperation principle. Conversation is governed by the cooperation principle. Conversation partners cooperate with one another:

Quantity: the amount of each participant’s contribution. Contributing neither too much or too little information.

Quality: contributions should be truthful, based on sufficient evidence

Relevance: input should be relevant to the topic of conversation.

Manner/clarity: Each participant should be direct, avoiding ambiguity, vagueness, and wordiness.

Lecture 6: Precursors to Language Development

Biological preparation.

Biological preparation is the strongest evidence for a genetic basis for language acquisition. All children learn to talk; all cultures have language; all normal children learn language in the same way, at the same rate.Lateralization or asymmetry of the brain, dominance of one hemisphere may be necessary for language development. So it’s a good sign if a child shows handedness early on. It’s not present at birth: it must develop. It should be complete by age 5 or so. Children who are not clearly dominant tend to have some language delay but they typically catch up without any intervention.Plasticity means flexibility when used in reference to the brain. It means that if brain damage occurs another part of the brain may take over functions of the involved area.

Through interactions with caregivers children learn language concepts. Cargivers are systematic, and quite repetitive. They repeat every utterence several times. They do so in the same manner/systematic. Children learn the power of language (when the child uses gestures to get things he/she wants it is very powerful). During the illocutionary period; they begin to point in order to request, signal, etc.
It is called the directive function of language: intentionally directing the actions of others.The representational function of language: to point things out and label them.
Interactions with caregivers help children organize information and develop a categorization and storage system.

Lecture 7: Piaget's Ideas Regarding Cognition/Language Development

Organization is a child’s inborn tendency to combine and integrate schemata (plan or scheme) into coherent bodies of knowledge (systems.)

Adaptation:

Adaptation is a child’s inborn tendency to adjust to the environment.
It has two parts: Assimilation and accommodation
Assimilation: child interprets new information by incorporating it into existing schemata (no cognitive change is needed).
Accommodation: the child modifies existing schemata in order to incorporate new information experiences, (cognitive change occurs to accommodate new information.)
An example of assimilation is when a child learns the concept of bird as the caregivers point out birds in the neighborhood, then is taken to a park and sees a swan for the first time. The swan is pretty similar to the child’s concept of bird, so the knowledge of “swan” can be assimilated.
Example of accommodation: later, the child sees a bat. This is too difficult to be assimilated, so this experience must be incorporated via accommodation; a new category must be formed. With accommodation there is a cognitive change.

Equilibrium:

Equilibrium is a balanced or harmonious relation between one’s thought processes and the environment. There is a balance between incoming sensory perceptions and existing cognitive structures. This is some of what drives learning. All organisms strive for equilibrium. Equilibrium is necessary for learning generally, including language development, although occasional disequilibrium aids in learning/memory, (remembering where you were when you heard about a startling event.)
In terms of development the ability to communicate develops before oral language (speech). Speech greatly enhances the role previously filled by gestures, intonation, facial expression and body language.

Lecture 8: Transition from birth to the one word stage

Precursors to linguistic content

There are many precursors. I am including only some of the most important:

1. 4-8 months – differentiated actions with objects, e.g. crumpling and tearing paper. 8 months is outside limit for normal here. If they aren’t doing it at 9/10 months, there is a problem.

2. 8-9 months dropping/throwing things intentionally. This should be encouraged as parents treated as a game, not punished - positive correlation between behaviors with objects at 10 months and later language development.

3. 8-12 months Object Permanence: the understanding that objects, animate and inanimate, continue to exist even when they are not in view. Basics should show up between 8 and 12 months. Beginnings of representational ability.

4. Means-end skills: ability to solve problems mentally. The child thinks about solving a problem and then figures out how to do it. Example: the child pulls on a tablecloth to move an object closer to him/her. This shows intentionality. There is a positive correlation between means-end skills at 9 months and later language development (Bates). It is a prerequisite for cause and effect.

5. Causality: understanding that one’s behavior can affect and be affected by other people and objects in the environment. At 11 or 12 months the child is aware that crying will bring attention. By 18 months, the child is aware of causal relationships between other people and objects. By 24 months s/he can classify own and others’ behaviors based on consequences.

6. Showing objects to others: this should happen between 12 and 16 months; there is a positive correlation with later language development.

7. Symbolic Play: an example is use of a spoon to represent an airplane-positive correlation between this ability at 18 months and later language development.

The perlocutionary period

The perlocutionary period is from birth to 7 months. Without conscious thought the child communicates his/her needs through cries and facial expression. None of the cries or gestures that s/he makes are intentional. During the perlocutionary period the child does not intend to communicate, but parents interpret vocalizations, gestures, etc. as communication. This adult morphizing helps bring the child into intentional communication.

The illocutionary period:

It begins around 7 months and ends around 12 months. The child communicates through gestures and vocalizations that are meaningful and precede the first true words.

In terms of development, the ability to intentionally communicate develops before speech. At age one, speech takes over the role previously filled by gestures, etc. Finally the child is using words to convey meaning. In fact meaning drives word order through the two, three and four word stages.

The locutionary period:

The locutionary period begins around 12 months or when the child begins to use words to communicate. Some normal children may not talk until 18 to 24 months.

• Variegated babbling 11-14 months adjacent and successive syllables are different. Instead of “dada” the child now says “dad” It has the intonation of adult speech. (Up to 9 months all babbling sounds about the same, regardless of language environment.)
Phonetically consistent forms (pcf) or vocable are used consistently and meaningfully by the child but aren't’t related to adult name for referent. An example”bon” for cat. Later when s/he develops the first word it will be “kitty” or "kah" and later cat. The child may develop up to 12 pcfs before producing his/her first true words.

Lecture 9: One Word/ Holophrastic Stage

This usually begins at 11 or 12 months due to use of daily verbal rituals, motherese, and parents' encouragement to act upon the environment. These things are essential for language development. It lasts until about 18 months when the child begins to use two word utterances.

Some of the first words are called holophrases. This refers to their status as one-word sentences. Meaning is expressed through intonation. The term holophrase is used because many linguists consider a child’s single word productions to be primitive sentences. So they have been called single word sentences. These productions must be true words. They cannot be formed by phonetically consistent forms (pcfs) or vocables.

The criteria for true words:
1. They must be used meaningfully and consistently.
2. They must bear a phonetic relationship to the adult term for the referent.

So, these productions are consistent approximations of words adults use .
Phonetically consistent forms indicate that true words will soon follow.
For example: a child hearing a knock on the nursery door says “mama”? questioning. When the mother enters the child says “mama!” greeting; then reaches to be picked up saying “mama!” again- commanding. So depending upon intonation and context, the same one word utterance can be a question, a greeting, or a request/command. The first true word has elements of phonology, morphology, semantics and pragmatics. The only element missing is syntax. That has to await the two word stage which begins around 18 months.

Phonological characteristics

First words are usually consonant vowel CV or vowel consonant VC syllables. CV first develops without reduplication then develops reduplication, CVCV later in this stage. Closing the syllable:, CVC, develops toward the end of this period. So, a child would first say ma, then mama, then mommy then mom; labials and dentals predominate. Plosives are the most common manner of production and /i/ /a/ /u/ of the “vowel triangle” are the most common vowels.
Children will have favorite sounds and avoid words containing sounds that they can’t produce. They also employ phonologicalprocesses or systematic procedures for simplifying adult productions. Example: reduplications, consonant cluster reductions, and diminutive forms (mama).

Grammar

During the one-word stage there is no syntax .The child’s production is all content, although tonal changes can change the meaning of their one word utterances. Paula Menyuk calls this primitive grammar, and used the term holophrase to mean a one word sentence.

Semantics

By 18 months the child will have a vocabulary of about 50 words. Of these, 60-65% will be noun-like, and fewer than 20% will be action words. These verb-like words appear soon after the first word. They will not be true verbs. They will be words like down, night-night, no, off, etc. True verbs don’t show up until later.
Modifying words (adjective like) also appear soon after the first word, but account for 10% or less of the first 50 words.

Personal social words like “hi” and “please” make up less than 10% of their first 50 words.

First words tend to be mid-level in terms of generality "Hi dog (over extending/generalizing), or terrier (under extending/undergeneralizing-calling all dogs terriers).

At this stage children's meaning for words will be different than adults. Their word meaning will be much more concrete. They use almost no abstractions. The child will talk mostly about his/her own world. During the beginning of this phase, the child can talk only about immediate surroundings. After about 18-19 months s/he will start to refer to things not physically present; s/he will say “daddy” when he’s not there. Even at this age, most speech refers to the immediate environment.

The child’s semantic markers/features are far fewer than those of adults. Example: the child may use “doggie” to refer to dogs and other animals that have four legs. They may call horses “cows.” Later, as they add to their repertoire of semantic features they learn that dogs bark which excludes horses and cows. As children add semantic markers their word meanings get closer to that of adults. So when they have a new vocabulary item it is not the same as the adult version.
The semantic features of words expand through experience. When I was a child an airplane was a metal bird. When I went through pilot training I added vastly to my features for airplane. They include rudder, yoke, and aileron.

Refining Word Meaning

Underextension:

Children use overly restricted meanings so that their words contain fewer features than the adult. Example: using the word cup, only for a sippy cup. This occurs in both expressive and receptive language.

Overextension:

Overextensions are meanings that are too broad and contain too many exemplars: calling all men “Daddy.” It usually occurs in expressivelanguage.

Word Categories

Substantive Words:

Substantive words are specific entities or classes of entities that have certain sharedperceptual or functionalfeatures. They refers to particular objects or classes of objects.
Nouns are typically used within this category.
At the two-word stage they will become cases: agent, object, location, dative, etc.

Relational words

They refer to relationships between words. For example the agent word (typically the initiator of action) as in “Daddy throw.” Throw would be a relational word. Another example: asked where Daddy is the child says “in house.” So Daddy is a substantive word and “in” a relational. Grammatical words like in and on, action words, and modifiers are relational. Some relational words are called proto-verbs: that, here, no, gone, more, again, and bye bye.Attribution (adjective like) relational words: mark the attributes, characteristics, or differences between similar objects. For example: cold, and yummy (icecream). These are rare in single and early multi word utterances. They seem to be used more as names than as properties at this point..

Concept Formation

Clark – semantic features hypothesis

The idea is that all referents can be defined by a universal set of semantic features like animate/inanimate,and human/nonhuman etc. Children establish meaning by noting perceptual features (vision, taste, hearing, smell.)Shape is the most salient of these features.Color doesn't’t seem to be very important to young children, yet so many teachers think that learning colors is very important.

Nelson – functional core hypothesis

The idea here is that in motion, dynamic features are salient features from which child derives meaning, vs. static features. So looking at things like actions, sounds, changes.

This can be related to learning by doing.

So a piece of chocolate would be something you can eat vs. a square brown object. A cat is something that lives in your house vs. a four-legged, furry pet.

In reality, both hypotheses represent what children are doing.

Early Pragmatics

First words occur as requests for information, help, or objects, or as comments, etc. Basically, pragmatic functions that develop earlier in the pre-symbolic period (illocutionary) carry over to the locutionary period. Their roles now fulfilled by words, were previously fulfilled by gestures or vocalizations.

Presupposition

Very young children lack pre-suppositional skills. Presupposition is the process of assuming which information a listener possesses or may need. They assume that their perspective is the same as yours. You know what they know. They will talk about people as if their listener knows who they are.

Labeling/requesting: these pragmatic behaviors are seen as the child is entering the one word stage. Requests previously using gesture and vocalization are now using speech, albeit one word utterances.

Lecture 10: Multi-word Stages

The term multi begins with two. For example a plane with two or more engines is called a multi-engine plane.The two word stage usually begins at about 18 months (MLU of 1.5 years) Most children are using a lot of two word utterances at 24 months (MLU of 2).

• Roger Brown: when children start to combine words into multiword utterances (2 words and longer) they do so in a predictable pattern that seems to be universal.

*Cognitive growth has a big influence on early two word combinations. Many of the principles of cognitive learning can be applied to language learning. Language is part of cognition.

Grammatical constructions also reflect cognitive development. The ability to embed a clause or phrase depends upon the ability to manipulate two or more objects. The child must be able to perform the operation cognitively before he/she uses it linguistically.

The child produces longer utterances as memory processing skills improve.
Two-word utterances represent more complete speech acts because the content can be communicated with less dependence upon non-linguistic cues.

Transition to the two-word stage

Just before the two word stage children will use single word approximations of adult phrases: “what’s that” – “wassat.”
They also use empty forms (two phonetic forms used consistently but have no referent (meaning). Bloom uses the examples “Mama didi” “dada didi.” While they are used consistently they are not meaningful like successive single word utterances.

The reduplication of single word utterances such as “mama mama” is a sign that child is almost ready for two word stage.

Successive single-word utterances

They have the intonational and stress pattern of two separate utterances (occurring horizontally) that relate in a meaningful way. This is the most important clue that the two word stage is about to begin.
Characteristics that differentiate them from two-word utterances includes pitch contour (falling pitch at the end of each word and equal stress on each word with a pause between words).
"Mama:" falling pitch
Pause
"Eat:" falling pitch

A two-word utterance would have no pause between words and would have a falling pitch after the second word. Mama (no pause) eat (falling pitch).

Two word stage

The two-word stage begins when there are two meaningful words that have no falling intonation or pause after the first word. The intonation would occur after the second word.
Word order is not fixed yet, but it will begin to be around 18 months

Semantics: the child knows about 50 words by 18 months when s/he first starts using two word utterances.

Syntax: at this point, word order begins to be important, but meaning is what dictates sequencing. In other words a semantic strategy is used to sequence at the two word stage and later at the three and four word stages.

Reflexive (two term) relations

A sub group of these rules develop earlier. They are called reflexive relations. They are more like single words. These kinds of utterances are usually mastered by 15 months and dominate the two-term relation category until age two. But by 18 months this sub group will no longer be considered reflexive.

Semantic-syntactic rules are semantic because the strategy for combining words is semantic, and they are syntactic because there is word sequencing. It is based on case grammar (Fillmore & Schlesinger). The word order is based on the semantic role (case) of a noun.
• Case grammar is used to describe language development at the 2, 3, and 4 word stages.

A Case is the semantic role for a noun. The following case relations are based on MacDonald’s adaptation of the work of Fillmore, Scheslinger, Brown, Bloom and others. McDonald uses the following cases for his Elicited Language Inventory (ELI) assessment and remedial instrument:Agentive: the perceived typically animate (alive) instigator/initiator of action. It doesn't’t require animation when used by a child. (He spilled a drink.)Dative: the animate being affected by the action named by the verb (indirect object). (He threw the ball to Mary.)Locative: the place, location, or spatial orientation of the state, or action of the verb. (The paper is on the chair.)Objective: the animate or inanimate noun where the role depends on the meaning of the verb. It’s the most semantically neutral case. (I saw her. She is (copula) nice.)

Lois Bloom was one of those who started the semantic revolution. She felt that child language should be examined based on the intended meaning of the speaker, using a rich interpretation that incorporated both linguistic and nonlinguistic cues. Meaning develops prior to syntax; that is content develops before form.

Case grammar seems to be especially useful for the analysis of the structure of early multiword utterances. A case is the semantic role of a noun, e.g. “Mommy house” meaning her location.

MacDonald’s eight rules seem to account for about 70% of children’s two-word utterances. When doing an assessment, if you find that a child is using most of these (congruent with age) he/she probably doesn't’t need therapy for a grammatical or semantic problem.

Agent + action: An agent is an animate being who instigates action according to case grammar rules, but have to remember that children have different ways of defining animate; “door close” could be agent + action to a child. Certainly “baby eat” would be. You must know or infer the context. “Bobby play,” “Mommy read," “Doggie run.”

Action + object: In this rule the semantic role of the noun is to be acted upon.
“ hit kittie” The cat was hit by the car.
In case grammar cat is in the objective case.

Agent + object: Not so common. The action word is understood
Daddy (is throwing) the ball.

Remember these concepts develop before the two-word stage. The child is just learning to express them with semantic-syntactic rules now.
“All gone” is not an example of this rule. It’s close in meaning to non-existence, but as it has no negative word. It is not a rule of negation.

The dative is the animate being that receives the indirect action of the verb. The X is usually an action word. (They are not called verbs yet.)

“Throw Alex” throws the chalk to Alex.
“Present Aiden” gives a present to Aiden.
This is the least common of these rules. It’s so rare that MacDonald dropped it from the ELI. He still retained eight rules by splitting one rule into two. This will tell you how arbitrary rules of language can be.
Remember, only nouns are cases. So if you are asked to give the case of a verb like "gave," you can't.

These two term utterances can only be understood in context. Without context or meaning, one cannot determine which rule a child is using.

The three and four word stages

According to Roger Brown children move from the two-word to the three-word stage by combining or expanding two previously acquired semantic-syntactic rules. What’s happening here basically is that children are putting together the two term relations they already know to make longer utterances using both strategies (combining or expanding).
Combinations are predominant at the three-word stage while expansions are seen more often at the four word stage.
Moskowitz doesn't’t make a big distinction between three and four word stages. She feels that the four word stage may develop due to increase in memory span..

At age two when a child’s mean length utterance (mlu) is two, s/he’s starting to use some three and four-word utterances. The average child is producing four word utterances by age two. Mean length utterance corresponds with age up to age five. A typical five year old has an MLU of five words.

Example: “Mommy cookie hot?” Asking if the cookies are hot and if she can have one.

The combining of agent + action and action + object is the simplest type of three word utterance.

For a four-word utterance the child typically goes from a three word-utterance such as agent+action +object by using a modifier. So we get "Mommy throw red ball." (red ball-modifier +head).

The following therapy is based on naturalistic principles:

Adaptive Motherese is a naturalistic type of therapy that uses the characteristics of motherese in a meaningful way to help a child learn language. It can even be taught to a parent who does not use motherese naturally, so he/she can teach his/her child language. Adaptive motherese is used in an action oriented therapy, whether it be making cookies or playing catch. Before the session begins, an SLP would want to make a clear list of the core vocabulary to work on so that the day’s goals can be achieved. This core vocabulary is worked on during an activity that is systematic and repetitive. This ensures that the words are learned in the same context and the child really gets the meaning out of them. During the activity, the SLP’s role is to ask the child questions. If you are playing catch, ask the child, “what are you doing?” If they were to reply, “throw ball,” you would provide a good linguistic model by expanding their utterance by saying something like, “ yes, you threw the ball,” and may even extend their utterance by adding, “ you threw the white ball.” Another way to elicit utterances from the child is to use fill ins. You may say to the child, “ you threw the _______?” and wait for “ball.” From that point you would want to expand and extend again. It is important to stay in close proximity to the child throughout the therapy session, and to have a clear cut beginning, middle and end of the activity. This will guarantee that the child gets good linguistic models after every utterance, and also be a part of a routine and experience completion. Adaptive motherese works the best as a multisensory therapy. The child will become very involved and be ready to learn when he/she is getting stimulation from all directions. Lastly, you want to use natural reinforcements with adaptive motherese instead of rewarding with tokens, such as stickers or candy. The best way to do this is through naturally occurring contingencies. When a child asks for something, like a cookie or a high five, give it to them. This teaches them that language is powerful, and by using it they can get what they want or need (Cassie Ragsdale, student in CMSD 451, Fall, 2008).

Lecture 11: The 9 Morphological Inflections/Allomorphs:

Some of the inflections included in Brown’s list of 14 morphemes can be considered as a group to constitute the next milestone in the child’s language development, mainly because they are really difficult for children. This is where a child who’s having problems with language might flounder.

1. Ing is acquired around 28 months or earlier. It is easily acquired by most children.

2. Plural /S/ /Z/ /IZ/. This should develop shortly before age 3 if the child does not have a problem. It is difficult to learn because the child is exposed to so many different models, as well as the short duration of the allomorph.

3. Possession /S/ /Z/ /IZ/. Should be learned by age 3 or a little after (before 3 ½).

This is not about the concept of possession, just a new way to express it.
This was previously expressed as modifier + head recurrence form: “nuther cookie”, “more milk.”
The possession concept is probably acquired at one word stage or before. In case grammar it is expressed as modifier + head: “my teddy,” “mommy sock.”
“mommy want chocolate candy” Four word stage, but prior to the possessive inflection.

4. Regular past tense /t/ /d/ /Id/ acquired by 3.5 or a little after.

5. Third person singular regular present tense verb is acquired after 3.5. Note that this morpheme has the same phonemes as with plural and possession.

So from 2.5 to 3.5 or four the child moves from ing to 3rd person singular/regular verb.
According to Brown, a child is said to have not developed a morpheme unless he/she’s using it in 90% of obligatory contexts. But if child is using these 60% or so of the time at the above ages, they are probably acquiring language normally.

If a child attaches the plural inflection to the word boy to make boys that is obligatory and it's marked. The word man doesn't take an allomorph, because its irregular. The plural is men. So that is not marked.

6. When the auxiliary "to be" in the 3rd person singular (e.g. she is listening) is contracted to (she's listening) the /z/ sound after she is an allomorph.

7. The copula 3rd person singular "to be" when contracted the z sound is an allomorph.

Remember that in this dialect the allomorphs of plural and possessive are often omitted due to phonological and morphological rules.

BE Phonological rule: if there is a consonant cluster at the end of a word and the last two phonemes are voiced voiced (vd vd) or voiceless voiceless (vl vl) the last phoneme is deleted/optional e.g. slep/slept
This rule affects plural in BE. Dog+plural = dog cat+plural = cat because of the vdvd and vlvl consonant clusters
So when assessing a speaker of black English he/she may not use an inflection for verb tense as a marker since it optional. One wouldn't’t expect to see plural or possessive marked unless the word ends in a sibilant or a vowel e.g. dish+ plural in BE is “dishes. Shoe + plural in BE is “shoes.” Grammatically, plural and possessive are marked/inflected/allomorphs but their non-use will be because of a final consonant cluster that is vd vd or vl vl at the end of a plural noun.

BE Morphological rule:
The 3rd person singular of regular present tense verbs is unmarked (optional) in BE vs standard dialect in which it is always marked.

Run+3rd. person singular in BE: run
Talk + plural is “talk” in BE.

Lecture 12: Development of Auxiliary and Copula

Conjugation of the verb to be:

I am (first person singular)

You are (second person singular)

The girl (she) is (third personal singular)

We are (first person plural)

You are (second person plural)

The boys (they) are (third person plural)

The auxiliary and copula are considered a milestone because they are hard to learn, and because certain adult sentence forms such as verb negation, interrogative reversals, wh questions and passives can’t develop without them.

Copula: is the verb to be used as a main verb. The uncontracted form is learned right after possession, at 3+ according to Brown’s list of grammatical morp hemes.

So at this point, the child can say, she is nice.

At 4+, after the uncontracted auxiliary is learned, the child learns the contracted form of the copula. She’s nice. This is also a morphological inflection. It has become a bound morpheme, a suffix. This means that the child now has two allomorphs for the copula: /s/ and /z/. The have already used these two for three other morphemes. May not need remediation due to generalization.

Auxiliaries are helping verbs. ( In Caesar’s Gallic wars he referred to his non-Roman soldiers as auxiliaries or helpers).Primary auxiliariesto be, to have, to do are used to form tenses. Have, had, has are perfective auxiliaries. Had gone is an example of the past perfect tense. Future perfect: she will have gone; I shall have seen. (you don’t need to memorize this)Secondary auxiliaries/modals – express mood or attitude. Ability (can), permission (may), intention (will), possibility (might), obligation (must, should),and ability (could).
The uncontracted form of the aux “to be” is acquired at 4+ in Brown’s list. “to do” is acquired later and the modal forms even after that, not being used very commonly until about 4 l/2. Both copula and auxiliary become inflections when contracted.

Remember allomorphs are formed by morpho-phonemic rules. These are variations of morphemes that occur in specific phonetic environments.

do, have, and will are used by most children by 4 years.

Ages at which 50% of children will use certain verbs:

26 mo. – do, have (very basic form)

30 mo. – can, be + present progressive, will

33 mo. be going to,

36 mo. have got to,

39 shall*

40 could*

41 should*

*These are learned later because they are semantically quite complex.

According to Laura Lee the auxiliary/copula to be is difficult to learn in the present tense because it is strictly a syntactic device. It adds no semantic weight (meaning) to the utterance.
Bobby is running vs. Bobby running
In other tenses such as the past and future, it does have semantic weight:
Bobby was running vs. Bobby will be running.

With children who have language problems the auxiliary/copula is usually delayed.

This is why it’s such a big jump from present progressive without the auxiliary to be (mommy running) to present progressive with aux. (Mommy is running)

Contractible auxiliary is the last of the morphemes on Brown’s list. Learned at after age 4.

Development of the auxiliary is crucial because verb negation, interrogative reversal, wh questions, tag questions and the passive cannot develop without it.

Auxiliary/copula verbs are the only ones that can be inverted to form questions or that can have negative forms attached to them (The copula can also do these things:
Is she sick? This isn't’t funny.

Also, auxiliary can be used to form elliptical responses: Who can go with me? I can
Also, to add emphasis: I did do it. I would do it.

Lecture 13: Verb Negation

Verb Negation is quite difficult as the verb must carry negation and tense at the same time. This is advanced syntax. Remember, the concept of negation is learned quite early.

The development of negation from the beginning:

Prelinguistically with gestures. Head shake learned at 10-14 months.One-word stage: “no” is generally one of the child’s first 50 words. Also “don’t” which is a vocabulary item at this point. Not a contraction of do not. It is the same as no.Two-word stage: negation + X: no run, no daddy etc.Three/four-word stage: negation +X is used along with another semantic/grammatical rule: “not Bobby running” (3 word stage) to “Bobby not running” embedding of the negative at the 4 word stage.
Morphological inflection stage – negation is the same as above or perhaps “Bobby no runs.”
Verb negationIt occurs after the auxiliary to be is acquired: Bobby is running. This means that the child can go on to form the adult form of the negative. Verb negation doesn't’t happen the next hour or even the next week or month. The child continues to use “Bobby is running” but with negation “Bobby not running” or “Bobby no runs” for a while.
Bobby is not running: verb negation (is + not+ verb)Verb negation contracted: “Bobby isn't running” or “Bobby’s not running.” This will take a while as there are varied models.

After to be is used as an auxiliary in verb negation the child can go on to use to do, then the modals etc.
Bobby does not run, Bobby doesn't’t run (aux.). Bobby is ill and shouldn't run (modal)
Bobby can not run, Bobby can’t run (modal)

Lecture 14: Early Question Development; Various Stages:

Pre-linguistic stage – puzzled expression as contingent queries, maybe some type of gesture, gaze (joint reference).One-word stage: rising intonation pattern is used as well as some variation of “what” like “wassat.”Two-word stage: use intonation and use wh question introducer (Roger Brown) “where mommy?” “Mommy house”? ( X+ locative).
what, where, who.
Three and four word stages intonation continues to be used with semantic grammatical rules. “Mommy eat kitchen (agent+action and X+locative)
When and why develop later as the child develops time and causation concepts. During the morphological inflection stage: question form continues as above but with inflections, What doggie eats, mommy eats dinner.
After developing the auxiliary the child will continue to use above forms for a while. Then s/he will begin to use reversals is mommy eating. For the first time,question form is signaled by syntax. First reversal generally occurs with the copula. Still what doggie eat or is doggie eating, need next step for adult form of this one.Wh questions next step. These necessitate an interrogative reversal + a wh word, meaning that the unknown comes at the beginning. What is doggie eating? Will generally start to do these with the wh words that are acquired first. Contractions develop in both aux and wh questions

Tag questions

This is a very difficult syntactic structure. It requires mastery of both verb negation and the interrogative reversal. As both elements are very complex, their combination is really hard. So, if a child is using tag questions, their language has to be quite good.

If first part of tag is affirmative, second will be negative. Example: “You understand that, don’t you?”
If first part is negative, the second part is affirmative. Example: “You don’t understand that, do you?”

Before real tags are learned, child might use “okay” as a tag. Next s/he will use the tag form without negation “You like cookies, do you?” Fully developed form shows up in early school age.

Interrogative reversals

This basically means a yes/no question. Subject and verb are reversed. “She is” becomes “Is she?”
This develops around the same time as verb negation, also requires the auxiliary. This is the first syntactic rule for questions. Up to this point, questions have been based on intonation. After the interrogative develops, the child can go on to develop wh-question

Question forms used by slightly older children and adults

1. Interrogative reversals or Yes/no require only a yes or no response are typically formed by adults either by adding and reversing the aux (are you eating snails?) or by intonation

2. Wh question forms require a more detailed answer, using an interrogative reversal and adding the wh word to the beginning of the question.

3. Tag questions are a combination of the interrogative reversal with verb negation. You understand that, don’t you? You don’t understand that, do you?

At this point the average child has acquired the basic rules of phonology, syntax, and morphology. Phonology may not fully develop until age eight. Syntactic rules will become quite sophisticated as the child learns to develop multiclausal sentence structure. Semantics will continue and become more and more sophisticated. Pragmatics too will continue to be fined tuned as the child experiences a variety of communicative settings.